Accuracy of self-reported history of autoimmune disease: A pilot study.

Research associating the increased prevalence of familial autoimmunity with neuropsychiatric disorders is reliant upon the ascertainment of history of autoimmune diseases from relatives. To characterize the accuracy of self-report, we compared self-reported diagnoses of 18 autoimmune diseases using an online self-report questionnaire to the electronic medical record (EMR) diagnoses in 1,013 adult (age 18-70 years) patients of a primary care clinic. For the 11 diseases meeting our threshold observed prevalence, we estimated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for self-reported diagnoses under the assumption that EMR-based diagnoses were accurate. Six diseases out of 11 had either sensitivity or PPV below 50%, with the lowest PPV for dermatological and endocrinological diseases. Common errors included incorrectly self-reporting type 2 diabetes mellitus (DM), when type 1 DM was indicated by the EMR, and reporting rheumatoid arthritis when osteoarthritis was indicated by the EMR. Results suggest that ascertainment of familial autoimmunity through self-report contributes to inconsistencies and inaccuracies in studies of autoimmune disease history and that future studies would benefit from incorporating EMR review and biological measures.